1. Technical Field
The present invention relates to an optical characteristic measuring apparatus and an optical characteristic measuring method for measuring optical characteristics such as a film thickness of a sample.
2. Related Art
Conventionally, an optical interference method using the phase of light is known as a method for measuring optical characteristics such as a film thickness (for example, JP 2008-286583 A and JP 2010-002327 A). In the optical interference method, a spectrum of light reflected by the sample to be measured is measured with a spectrometer, and the optical characteristics of the sample are measured by analyzing data of the spectrum.
JP 2008-286583 A discloses an optical characteristic measuring apparatus that improves precision in measurement of optical characteristics by facilitating focusing on a sample (object to be measured). In JP 2008-286583 A, spectrum measurement of reflected light is performed after a user changes the positional relationship between the sample and an objective lens with reference to the state of a reflected image shown by a display or a controller performs focusing using an automatic focusing technique. The optical characteristic measuring apparatus of JP 2008-286583 A has a mechanism for focusing, such as a camera and an observation-purpose light source and employs a complex optical system incorporating optical components for using this mechanism.